245/50 R17 doesn't belong to the most popular dimensions for summer tyres - there are 1 tyre models available, which can be compared to 155/60 R15, 170/60 R17, 160/60 R14. Let's break down the sizing - 50 is height of the tyre, which is calculated as 50% of the tyre width (245mm), which means the sidewall height has 122.5 mm. The wheel diameter is R17, which means it fits to a 17 inch/431.8mm diameter wheel. The total circumference of the tyre is 2126.23 mm, which is very similar to 225/60 R16(2124.97 mm), 275/40 R18(2127.49 mm), 245/45 R18(2129.06 mm), 275/35 R19(2120.89 mm), 245/40 R19(2131.88 mm), 285/30 R20(2133.14 mm), 225/55 R17(2134.08 mm). There are multiple speed indexes available for summer tyres in 245/50 R17: W(270km/h), Y(300km/h). The same goes for weight indexes: 99.